Submersible motor driven pump



May 14, 1935- .JA wLNTRoATH 2,001,172

SUBMERSIBLE MOTOR DRIVEN PUMP May 14, 1935- J. A. wlNTRoATH 2,001,172

SUBMERSTBLE MOTOR DRIVEN PUMP Filed Feb. 2l, 1931 2 Sheets-Sheet 2 Z4 l27 DI 2 gk 7a 74 :fifa/Wei Patented May I4, 1935 UNITED STTES PATENTOFFICE to Wintroath Pumps,

Ltd., Alhambra, Calif., a

corporation of California Application February 21, 1931, Serial No.517,481

3 Claims.

This invention relates in general to submersible motor and turbine wellpumps, this type of pump differing from the usual motor driven pump ofthe extensible line shaft type, in that the motor, in- 5 stead of beinglocated at the ground surface and connected with the pump by a shaftextending to the depth of the pump, is carried as a part of the pumpunit on the lower end of the eduction or discharge pipe and submerged inthe well liquid.

The present type oi' submersible pump has been developed with theprimary object of overcoming many of the undesirable and troublesomefeatures of the extensible line shaft type, and in order that theaccomplishments of the invention may be more fully appreciated, I shallmention briey at the outset some of the inherent advantages had by theinvention over extensible line shaft pumps. In the rst place, theprovision of a submersible motor obviates the necessity for the use ofline shafting extending from the pump to the ground, also the shaftenclosing tubing and the line shaft bearings required to journal theshaft at spaced intervals in its enclosing tubing. Furthermore theexpense in pump head construction `at the ground surface is reduced to aminimum in that substantially all that is required in the submersibletype is a simple connection with the eduction pipe which will serve toconnect with a line for conducting the liquid pumped from the well. Andagain, with the present type of pump,

no necessity arises for having to provide a ground surface housing, orother such means that may involve considerable expense, for protectingthe motor from the elements.

As is commonly known, wells in which it is required to install the pump,frequently are crooked and make wide deviations from the vertical, all

of which renders it impossible in an extensible line shaft pump to alinethe shafting and bearings properly, with the result that the shaft issubjected to crystallization and the bearings to severe wear. Suchdifficulties of course are not experienced with the submersible motorpump into gain the advantages, which will be readily apparent, of theuse of a small eduction pipe.

Further advantages are gained from the standpoint of manufacture andinstallation expense, in that the eduction pipe may be used in randomlengths, whereas in the extensible line shaft type, the eduction pipe,shafting and shaft enclosing tubing sections, customarily are requiredto be in exact lengths with relation to each other, with they resultthat each unit length of the combined parts 10 requires factoryconstruction.

I may state that one of the greatest, if not the greatest difficultyencountered in submersible motor pumps, is that of preventing leakage'oraccess of the well uid to the motor casing, and the point at whichleakage occurs is of course by way of the opening in the motor casingthrough Which'the drive shaft extends. Successful use of usual packingglands to prevent leakage into thecasing around the shaft, is impossiblebecause of the fact that the well liquid may be under such staticpressure as to force its way through an ordinarily tight packing gland,and also due to the fact that the packing gland soon becomes Worn to thepoint of permitting leakage, and no means is available for tightening itto compensate for wear. The problem of providing a fluid tight sealagainst the entry of well liquid to the motor casing is met -by theinvention through the provision of means comprising essentially a liquidseal, capable of excluding the well liquid, and so constructed as to befree from wear over an indefinite period.A I may state that other formsof this general type of liquid seal are described and broadly claimed inmy copending applications on Method of lubrication for submerged bearingstructure, filed June 18, 1928, Ser. No. 286,112. The present inventiondeals, in some of its aspects, with the utilization of this general typeof seal in submersible motor unit construction.

In the present pump, the motor operates in a lubricating oil within ythemotor casing, and the seal construction is such as to utilize thelubricant in the exclusion of the well liquid. It may be stated thatthis type of liquid seal is particularly adaptable for use in connectionwith submerisable motor units, in that it serves to take care oi' theexpansion or displacement of lubricant from the motor chamber occasionedby the pumping action of the motor or as a result of heating of themotor.

Although perhaps the most salient objects of the invention have to dowith the liquid seal and expansion chamber construction just referredto, the invention also includes within its scope, nu-

point all of the various objects and novel aspects of the invention,since these will be made self evident in the following description. Forpurposes of describing my invention, I have shown it to be embodied in atypical and preferred form of submersible motor. However it is to beunderstood that in So doing, I do not intend that the invention beregarded as impliedly limited to this particular construction, since itmay be embodied in pumps other than that specically shown, withoutdeparture from its intended spirit and scope. Reference is had forpurposes of description to the accompanying drawings wherein.

Fig. l is a general View of the pump suspended on the eduction pipebeneath the standing level of the well liquid;

Fig. 2 is an enlarged sectional view of the pump including the motor andimpeller units, certain parts of the motor section'being shown inelevation;

Fig. 3.is a further enlarged sectional view of the pumping or impellersection; and

Fig. 4 is a sectional view, on somewhat smaller scale of the lowerportion of the pump continuing from the lower end of Fig. 3.

Referring rst to Fig. l, the pump, generally indicated at Ill is shownsuspended within the well casing II on the lower end of the eductionpipe I2, the latter having a suitable head or fitting I3 at the groundlevel, which may connect with a discharge pipe I 4. The eduction pipemay be supported at the ground by any suitable means, such means howevernot being shown since it constitutes no part of the invention. The pumpI0 is lowered -to a point below the normal standing level of the wellliquid within the casing, or to a point such rthat the pump suctioninlet I5, hereinafter described, will fall below the level L of the wellliquid column when the latter is pulled down during pumping operations.f

I may conveniently describe, at this point, the

strainer, generally indicated at Ii, which serves to exclude fromentrance to the pump suction intake I5 foreign bodies carried by thewell liquid and which might cause injuries to the pump parts. Thestrainer consists essentially of a screen I1 of tubular formation andtapering toward its lower end I1b at which itis closed. The screen mayconveniently'be made from metallic sheet material cut so as to formspaced strips |1a, or the strips may be formed separately and arrangedin spaced relation as shown. The upper end of the screen preferably willextend suill-A ciently close to the wall of the' casing as to excludeparticles of any considerable size from being taken upwardly past thescreen. As a simple means for supporting the screen, I show it to becarried on a rod I2 depending from the lower end of Ithe motor casinghereinafter described, through the strainer and attached to the bottomI1b thereof.

The pump may be characterized as comprising an upper impeller sectionIa, and a lower motor section Illb, the latter being supported from thejimpeller section as will presently appear. 'Referring particularly toFigs. 2 and 3, the -upper impeller section is shown to comprise aseriesof units 20, each consisting of an impeller bowl or housingconnected to the next adjacent bowl,

the uppermost bowl 2 Ia being connected with the lower end of theeduction pipe I2 by way of adaptor or bearing housing 22. Connected tothe bottom of the lowermost vbowl is an annular casting 22a. which formsthe suction intake, the sides of said casting preferably being so formedas to flare downwardly and outwardly substantially as shown. Impellers22 one within each of the bowls 2 I are keyed to the pump shaft 24, theimpellers operating, upon rotation of the shaft, to displace the wellliquid taken in through inlet I5, upwardly through passages 25 in thebowls and into the discharge column in the eduction pipe I2. 'Ihe upperend of the pump shaft 24 is journaled in a sleeve bearing 26, supportedcentrally within adapter 22 by means of ribs 21. I may state that theadapter, bearing sleeve 26 and ribs 21 may conveniently be formed as asingle casting. The upper end of the bearing sleeve may be closed by acap 22. Preferably bearing 26 and the central bores 29 in the impellerbowls through which the shaft extends, will carry sleeves 2l of suitablebearing material.

It will be understood that the described pumping section is to beregarded merely as typical of any suitable form of turbine pump whichmay be used in combination with the motor section, and also that while Ihave shown a pump comprising a certain number and arrangement ofimpeller units, the invention contemplates the use of'any number and anysuitable arrangement, or number of stages of such units.

The motor casing 22 is supported from the pump housing by way of aseparating chamber casting or shell 22, the latter being joined to thepump suction intake casting 22o. Although shell 22 may be joined to orsupported from the pump housing in any suitable manner, it preferably isformed integrally with member 22a, and as a convenient method for sojoining these parts, I have shown them to be cast integrally, withinterconnecting webs 24 between which the well liquid is taken into thepump. Shell 22 preferably is tapered toward its upper end so as toprovide for maximum clearance and inlet opening between the downwardlyflaring walls of the inlet casting 22.

The motor casing 22 comprises a. cylindrical section 22a closed at itslower end by cap 22h, the joint therebetween being fluid tight. Asubstantiallycup-shaped bracket 25 'is threaded into the upper end ofthe motor casing, said bracket serving, as will appear, to support themotor assembly within the casing. 'I'he motor casing is attached toshell 22 by means of screws 65 extending through the bottom plate 22a ofthe shell and into the top ilange 25a of the bracket, a gashet 52 beingplaced between the shell and casing sections to provide a fluid tightJoint. The stator 22 of the motor is supported from bracket 25 and isshown to be attached thereto by screws 2lb; and similarly secured to thelower end of the stator is a lower cup-shaped bearing supporting bracket21 attached to the stator by screws 22. The rotor, Vdiagrammaticallyindif cated at.22a, 'is carried on shaft 29, the upper and lower ends ofwhich are journaled in thnlst bearings 4I and 4I carried in brackets 25and 21 respectively. The inner ball race 42 of the lower bearing iscarried on sleeve 44 bearing against annular shoulder 45 on the shaft,and is clamped between flange 44a on the sleeve and nut 45a. threaded onthe lower end of the shaft. The outer race 'ring 46 is seated within thecup shaped interior portion 31a of the bracket.

The upper end of the motor shaft is keyed to a sleeve 48 which bears atits lower end against shoulder 48 on the shaft, and the inner race ring5I of the upper bearing 48 is clamped between sleeve flange 48b and nut58. 'I'he outer race ring 52 is seated within the cupped interior of thebracket in a manner similar to the previously described outer race ringof the lower bearing. Preferably the bearings will be designed to takethe shaft thrust in opposite directions, the lower bearing taking the upthrust and bearing 48 the down thrust. Current is supplied the stator 88by way of conduit 53 leading to the ground surface, the lower end of theconduit extending into rthe motor casing through a fluid-tight packinggland 54 in the upper flange portion 85a of bracket 85.

I have provided at 55 a joint or coupling between the motor and pumpshafts whereby they may be relatively adjusted for ythe purpose ofproperly positioning the impellers 28 within the impeller bowls. It isto be understood that various forms of adjustable connections betweenthe shafts may be provided 4which will permit adjustment of the pumpshaft for the purpose mentioned, the illustrated type of connectionhowever being preferred for reasons of simplicity of construction andease of adjustment. The lower threaded end of the pump shaft 24 isslipped into the upper end of sleeve 48 and is secured against rotationrelative ythereto by key 55. Threaded on the pump shaft and bearingagainst the sleeve is a nut 51 which also is locked against turning onits shaft by key 88. In order to adjust the position of shaft 24relative to the motor shaft, the former may be slipped upwardly out ofsleeve 48 so as to permit removal of key 58, whereupon nut 81 may beturned on the shaft and keyed thereto in adjusted position; and the pumpshaft then reinserted in sleeve 48 with nut 51 bearing against the upperend of the sleeve.

A sleeve supporting ring 88 is secured by means of screws 8| to theunderside of the bottom plate 88a of shell 88, and into ring 88 isthreaded sleeve 82 which extends upwardly a suitable distance within theseparating chamber 54. The joint between ring 88 and shell 88, and alsothat between said ring and sleeve 82, will of course be duid-tight.Sleeve 82 may or may not be in close engagement with the shaft, but forthe purpose of indicating that fluid flow may occur from the motorcasing into the separating chamber, and vice versa, I have indicated aslight clearance space at 1I.

An inverted cup-shaped seal member 88 is secured to the pump shaft byset-screws 88, the joint being made fluid-tight by packing 18. Cup 88extends over and around the upper end of sleeve 82, and preferablydownwardly to a point near the bottom of the separating chamber in orderto provide for a maximum length of seal or displacement chamber. 'I'heseal cup is spaced fromsleeve 52 to provide what may be termed adisplacement chamber 18, the purposes and characteristics of which willappear more fully hereinafter. Carried within the upper end of shell 88is a bearing sleeve 14 which preferably, though not necessarily, has ajournaling fit with the pump shaft, the upper end of the bearing sleeveprojecting within an annular groove 15 in the lowermost impeller 28.Although bearing sleeve 14 may fit the shaft more or less closely,access of well liquid to the separating chamber will occur between thebearing and the shaft; and although such flow of well liquid into theseparating chamber may be more or less restricted, the static fluidpressure in the chamber will be substantially that of the static columnin the chamber itself plus the pressure of the well liquid columnstanding above the upper endof the separating chamber.

It will be noted that shell 88 serves to substantially enclose andsupport, independently of the well liquid, a liquid column standing theheight of the chamber. And therefore should for any reason the wellliquid level fall below the upper or inlet end of the separatingchamber, there will still be supported therein a column of liquidextendnig above the liquid seal formed by sleeve 52 and the sleeveenclosing cup 58. The advantages of so supporting a liquid column inconnection with the seal, independently of the well liquid, will be seento better advantage in the following description of the operation of thepump.

After assembling the pump unit prior to its lowering within the well,the motor casing 32 will be completely filled with oil, for example asuitable grade of transformer oil. 'I'he casing will be filled whilestanding in a vertical position and the lubricant introduced through anopening 88.in the lower end of the casing. Opening 88 normally is closedby a check valve 8| consisting of a ball 82 which seats under theinuence of a comparatively strong spring 83 bearing at its upper endagainst apertured plug 84. For purposes of filling the casing with oil,attachment of a lubricant line may be made to socket 85 before screwingthe screen supporting rod I8 thereinto.

The oil upon rising within the motor casing will force the air out aheadof it, and provision may be made whereby the oil will rise into space 188 at the outside of bracket 85, either by providing clearance betweenimpact tubes 81, hereinafter described, and openings 88 within the lowerportion of the bracket through which the impact tubes extend, or bydrilling holes 88 so as to permit direct flow from space 88 into annularchamber 88. Holes 8| are drilled inthe bracket at the upper end ofchamber 88 in order to permit air therein to pass into 'the bearingchamber 88. The casing ordinarily will be filled with oil to the pointof overflowing sleeve 82, and any overflow will pass downwardly ,throughthe displacement chamber 13 between sleeve 52 and the liquid seal member58 into the bottom of separating chamber 54. All the air within thecasing will similarly be discharged into chamber 54.

As shown most clearly in Fig. 4, a small bleeder opening 14c is providedat the upper end of the kdisplacement space 13. Assuming the mo- -torcasing to have been lled with oil as described, before theunit islowered within the well chamber 54 preferably is filled with oil up to apoint near the level of orice 14c. At this time the small plug in shell38 directly opposite orifice 14c will be removed. The oil introduced tochamber 84 will rise therein and also within the displacement space 18,and anyair present in the upper interior of 13 that would otherwise beentrapped therein in the absence of bleeder opening 14e, will beexpelled through the opening as the oil rises. When the oil has risen toa levelat or near the opening, and all of the greater portion of airwithin chamber 13 expelled, the opening may be closed by suitable means,access to opening 14c being had through the opening in shell 88 normallyclosed by the plug shown opposite opening 14c. Thereafter the plug willbe inserted within the shell opening.

The pump may now be lowered within the well and to the desired depth ofsubmergence beneath the surface of liquid in the well. At this timechamber 64 may become entirely filled with well liquid by restrictedleakage into the chamber at 14. If it is desired to preventcontamination of the well liquid as a result of the lubricant in chamber64 becoming displaced by well liquid after the unit has been submerged,the lubricant can be flushed from chamber 64, after the describedfilling operation, by displacing it with water poured into the chamberbefore lowering the unit into the well.

vAs the pump is started into operation, the motor will cause, by virtueof its pumping action, a certain amount of the oil to be displaced fromthe motor casing by overflowing the upper edge of sleeve 62, and theoverflow oil will pass downwardly in chamber 13 and stand in a column onthe surface of the well liquid that has risen a short distance withinthe lower end of space 13. In addition to the pumping action of themotor, a further amount of displacement of the oil therein will occur asa result of expansion due to heat generated by the motor. It may bestated with reference to the displacement chamber 13 that the volume ofthis chamber will be sufficient to accommodate or contain the overflowfrom the motor casing caused by the pumping action of the motor and theexpansion of the oil. And preferably the volume of the displacementchamber will be somewhat greater than the volume of liquid which at anytime will become displaced thereinto.

If the pump is shut down, the pressure of the hydraulic column inchamber 64 will tend to raise the air and lubricating oil columns in thedisplacement chamber 13 and to return the displaced oil to the casingvia space 1i. Return displacement into the casing may consist of the aircolumn in chamber 13 above the level oi' the lubricating oil standing onthe surfaces of the vvell liquid therein, or it may include a certainamount of the lubricant in addition to the air.

However, in any event the volume of fluid returned to the casing chamberwill be equal to that originally displaced, and the well liquid willrise no further than to its normal or original level in chamber 13.Since the air and displaced oil in chamber 13 are of lower specificgravity than the well liquid, it of course follows that by nopossibility can the well liquid itself rise to the point of overflowingthe upper edge of sleeve 62 into space 1 I.

I may state at this point that although the described method of firstfilling the motor casing with oil prior to lowering within the well willusually suiiice, it may be possible to carry out a similar fillingoperation so as to completely expel all well liquid and air from thedisplacement chamber, after the unit has been submerged in the wellliquid. Thus the unit may be completely lled with oil at the groundsurface as previously described, and an oil conduit 95 is connected bysuitable means to the bottom of the casing, for example the upper hollowend of rod I8, so as to enable oil from conduit 95 to be discharged intothe casing past the check valve. The pump may then be lowered in thewell and submerged beneath the liquid level therein, whereupon an Acient to displace from said chamber whatever air or wellA liquid thatmay be present therein. As will readily appear, the effect of thisoperation will be to provide a comparatively longer seal of oil in space13 to exclude well liquid 64 from entrance to the motor casing. As afurther possibility, chamber 64 in shell 33 may be filled with water orwell liquid at the surface of the ground, and oil then introduced intothe motor casing past check valve 8| to the point at which the oil willoverflow sleeve 62 and completely fill chamber 13 so as to displace allwell liquid therefrom.

During operation of the pump the well liquid being taken intothe inlet34 is drawn upwardly around the outside of the casing, and in flowingalong the wall thereof the liquid serves as an effective means forcooling the motor by carrying away the heat generated. In order toprevent excessive heating in localized zones within the motor assembly,I have provided means whereby the oil is permitted to circulate freelywithin the casing and thereby evenly distribute the heat. Althoughvarious means may be provided for accomplishing this purpose I haveshown, as typical, circulating or impact tubes 81 extendinglongitudinally of the casing between brackets and 31, tubes 81 openingat their upper and lower ends into chambers 93 and 96, respectively.Tubes 81 serve primarily to conduct the comparatively warm or hot oil inthe upper interior of the casing, downward into space 96 which iseffectively cooled by the well liquid flowing past well 32h, and bymaintaining this circulation, together with the pumping or circulatingtendency of the motor, the oil in the motor casing is maintained atproper low temperatures.

It will be noted that chamber 64 is substantially closed from the welland that the column of liquid therein is supported independently of thewell liquid so that the level of this independently supported column orwell liquid will at all times stand above the overow edge of sleeve 62.Therefore, if for any reason the level of the well liquid should fallbelow the pump inlet or the point of entry to chamber 64, the liquidseal for the motor casing will remain undisturbed, since the column ofliquid in chamber 64 will continue to exert an upward pressure withindisplacement chamber 13 to hold the overflow from. the motor casing inthe upper interior-of the liquid seal cup.

Although the space between bearing 14 and the pump shaft through whichthe well liquid has access to chamber 64 may be'more or less restricted,when the well liquid stands at a level above this space, the pressureexerted by the well liquid to support the displaced column of oil inchamber 13, will equal not only the hydrostatic pressure of the columnin 64, but in-addition substantially the static pressure of the columnof well liquid standing at the outside of the pump above the upper endof shell 33. The latter thus is effect-ive exerting an additionalpressure over and above that exerted bythe independently supported col-lumn in 64, which is effective inl holding up the volume of displaced oilin chamber 13.

Under certain circumstances it may be desirable to further increase thepressure within chamber 64 over that due to the static pressure of thecolumn therein end the column of well liquid standing above the pumpinlet. I have therefore made provision whereby a pressure equal to anypart of, or the total head developed by the pump may be communicated tochamber 64. A pressurecommunicating conduit 99 may be provided whichestablishes communication between chamber 64 and eduction pipe I2 at theupper discharge end of the pump unit Ilib.` In this case, neglecting therestriction to now oiered by the shaftlopening in the upper end of shell33, the pressure therein will equal substantially the total headdeveloped by the pump. In case the pump is constructed with a pluralityof pumping stages such as units Ilia, the pressure conduit 99 maycommunicate at any point between stages or beyond the last stage, asdesired. 'I'he effect gained by so communicating the discharge pressureof the pump unit to chamber 64 thus will be to maintain a higherpressure within the displacement chamber 13 than that representing thecombined static pressure heads of the column within chamber 64 and thewell liquid standing above the chamber.

I claim:

l. In a submersible well pump, a pump discharge pipe, a substantiallyfluid tight casing supported on said pipe, a motor in said casing,

'said casing containing a lubricating oil in which v introducing wellliquid to said displacement chamber at a pressure in excess of thestatic head of liquid standing in the well above said chamber.

2. In a submersible well pump, a pump discharge pipe, a, pump 'unitsupported on said pipe, 'a motor unit below said pump, said motor unitcomprising a substantially fluid-tight casing, a motor in said casing,and a motor shaft extending through an opening in the upper end wall ofthe casing and operatively connected to said pump; a shell providing adisplacement chamber communicating with said opening, and a conduitinterconnecting said shell with said discharge pipe at the dischargeside of the pump.

3. In a submersible motor well pump, a lubricant containing motorcasing, a motor operated pump, walls forming a well liquid chamber, sealmeans preventing leakage of well liquid from said chamber into themotor/ casing, and means for communicating through said seal means tothe motor chamber, a pressure in excess of the static head of liquidstanding in the well above said chamber, said means comprising a pipeconnect- 'ing the discharge side pf the pump with said chamber.

JOHN' A. WINTROATH. l

